Sure. But they aren't saying biological sex doesn't exist. They are saying there is sex and gender and that these two things can be different. Specifically sex

Sure. But they aren't saying biological sex doesn't exist. They are saying there is sex and gender and that these two things can be different. Specifically sex is biological, while gender is a social and physiological construct. What is explicitly NOT being said is that biological sex is non-existent. And they are saying that a person's gender may be female while their biological sex can be male (or ambiguous), and that these people should still be considered women. That's very different from saying biological sex doesn't exist.